Currently, the electric vehicle has been developed rapidly as the representative of the clean energy vehicle. However, there are some problems in the rapid development of the electric vehicle: the electric vehicle will influence the power system to a great extent when the number of the electric vehicles reaches a certain size and the electric vehicles are connected to the power system disorderly. For example, the power quality can be declined, the loss of the system power can be increased, and even the stability of the power system can be endangered. Therefore, it is necessary to optimize the charging behavior of the electric vehicle to avoid the above described effects, and to achieve that the charging power may be increased during the trough of the power system and may be decreased during the peak of the power system.